Vibration Characteristics of the Vocal Folds

2006 ◽  
Author(s):  
L. Hai ◽  
A. M. Al-Jumaily ◽  
A. Mirnajafi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Element Model ◽  
Vibration Characteristics ◽  
Transverse Isotropic ◽  
Body Theory ◽  
Oscillation Characteristics ◽  
Vocal Fold Nodules

The vibration characteristics of the vocal folds are investigated using a finite element model which incorporates the in-homogeneity and anisotropy of the materials and the irregularity of the geometry. The model employs the cover and body theory to build the structure of the vocal folds and implements measured viscoelastic properties of the mucosa and the transverse isotropic elastic properties of the muscles. It has the potential to simulate some vocal-fold disorders and determine the change in characteristics. To determine the oscillation characteristics of the folds, the eigenfrequency and eigenmodes of the finite element model are determined using the ABAQUS software. The model results compare well with some experiments performed on a silicon vocal fold. It is anticipated that the model will help to identify voice disorders such as vocal-fold paralysis and vocal-fold nodules.

scholarly journals Bayesian Inference of Vocal Fold Material Properties from Glottal Area Waveforms Using a 2D Finite Element Model

2019 ◽  
Vol 9 (13) ◽  
pp. 2735 ◽  
Author(s):  
Paul J. Hadwin ◽  
Mohsen Motie-Shirazi ◽  
Byron D. Erath ◽  
Sean D. Peterson
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bayesian Estimation ◽  
Material Properties ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Element Model ◽  
Lumped Element ◽  
Subglottal Pressure ◽  
Contact Pressures

Bayesian estimation has been previously demonstrated as a viable method for developing subject-specific vocal fold models from observations of the glottal area waveform. These prior efforts, however, have been restricted to lumped-element fitting models and synthetic observation data. The indirect relationship between the lumped-element parameters and physical tissue properties renders extracting the latter from the former difficult. Herein we propose a finite element fitting model, which treats the vocal folds as a viscoelastic deformable body comprised of three layers. Using the glottal area waveforms generated by self-oscillating silicone vocal folds we directly estimate the elastic moduli, density, and other material properties of the silicone folds using a Bayesian importance sampling approach. Estimated material properties agree with the “ground truth” experimental values to within 3 % for most parameters. By considering cases with varying subglottal pressure and medial compression we demonstrate that the finite element model coupled with Bayesian estimation is sufficiently sensitive to distinguish between experimental configurations. Additional information not available experimentally, namely, contact pressures, are extracted from the developed finite element models. The contact pressures are found to increase with medial compression and subglottal pressure, in agreement with expectation.

Influence of Vocal Fold Scarring on Phonation: Predictions from a Finite Element Model

2005 ◽  
Vol 114 (11) ◽  
pp. 847-852 ◽  
Author(s):  
David A. Berry ◽  
Haven Reininger ◽  
Fariborz Alipour ◽  
Diane M. Bless ◽  
Charles N. Ford
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fundamental Frequency ◽  
Viscoelastic Properties ◽  
Vocal Fold ◽  
Human Subjects ◽  
Vocal Folds ◽  
Element Model ◽  
Acoustic Intensity ◽  
Vocal Fold Vibration

Objectives: A systematic study of the influence of vocal fold scarring on phonation was conducted. In particular, phonatory variables such as fundamental frequency, oral acoustic intensity, and phonation threshold pressure (PTP) were investigated as a function of the size and position of the laryngeal scar. Methods: By means of a finite element model of vocal fold vibration, the viscoelastic properties of both normal and scarred vocal fold mucosae were simulated on the basis of recent rheological data obtained from rabbit and canine models. Results: The study showed that an increase in the viscoelasticity of the scarred mucosa resulted in an increase in fundamental frequency, an increase in PTP, and a decrease in oral acoustic intensity. With regard to positioning of the scar, the PTP increased most significantly when the scar was within ±2 mm of the superior-medial junction of the vocal folds. Conclusions: The systematic data obtained in this investigation agree with the general clinical experience. In the future, these findings may be further validated on human subjects as newly emerging technologies such as linear skin rheometry and optical coherence tomography allow the histologic and viscoelastic properties of the normal and scarred vocal fold mucosae to be measured in the clinic.

Vocal Fold Dynamics During Phonations

2007 ◽  
Author(s):  
H. Lan ◽  
A. M. Al-Jumaily ◽  
A. Mirnajafi
Keyword(s):  
Finite Element ◽  
Risk Factor ◽  
Finite Element Model ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Element Model ◽  
Glottal Closure ◽  
Vocal Fold Dynamics ◽  
The Impact ◽  
The Finite Element Model

During phonation, the vocal folds collision in the glottal closure is considered as a risk factor for pathology development. Based on the finite element model using the software ABAQUS™, the impact stresses between the vocal folds are studied.

Prediction of Modal Characteristics due to Design Change

1997 ◽  
Author(s):  
Tong Y. Yi ◽  
Parviz E. Nikravesh
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Stiffness Matrix ◽  
Element Model ◽  
Vibration Characteristics ◽  
Original Structure ◽  
Design Change ◽  
Modal Data ◽  
Modal Characteristics

Abstract This paper presents a method for predicting modal characteristics of a structure that is considered to undergo a design change. It is assumed that for the original structure the modal data is available either as a complete or as an incomplete set. Based on the available modal data and the known data on the design change, this paper discusses methodologies for determining the vibration characteristics of the modified structure. By considering practical situations, the emphasis of this paper is on structures for which a finite element model, and hence a stiffness matrix, is not available.

scholarly journals Modelling Bending Stiffness and Vibration Characteristics to Enable Simulation-Driven Ski Design

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 157
Author(s):  
John Borenius ◽  
Henrik Edman ◽  
Albin Lindmark ◽  
Marcus Pålsson ◽  
Thomas Abrahamsson ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Vibration Characteristics ◽  
Trial And Error ◽  
The Past ◽  
Design Changes ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Design Options

When developing alpine skis, new design is often built upon experience from what has been done in the past. This allows for stable but incremental improvements that limit the possibilities of ground-breaking design changes. To allow such major changes, without risking spending a fortune on trial and error studies, simulation-based design is a must. This paper presents a method for such a simulation-based design approach, focusing on the effect of the internal ski structure and its effect on bending and vibration characteristics. As a prototype ski, we have studied Faction Skis’ Candide 3.0, for which a finite element model was developed and validated. In the next step, the effect of a design ski variation was analysed to demonstrate how simulation-based screening of design options can be easily implemented.

Sign in / Sign up

Export Citation Format

Share Document